The long range objective is to advance the understanding of the hormonal effects on growth and maturation and on the endocrine physiology of the mother and fetus. The regulation of the secretion of growth hormone and prolactin will be assessed with respect to stimulatory and inhibitory activity of the hypothalamus and adrenergic receptor activity in man and in the dog. Physiologic mechanisms which affect the secretion of chorionic somatomammotropin will be elucidated utilizing the pregnant monkey as an experimental model. The identification of antigenic determinants on the growth hormone, prolactin, and chorionic somatomammotropin molecules will be studied utilizing a variety of immunochemical techniques.